1. Field of the Invention
The present invention relates to a method and device for controlling the sliding movements of a vehicle seat in order to adjustably move the seat between a given seating position and retracted position to permit a smooth climbing and descending of an occupant onto and from the seat.
2. Description of Prior Art
Climbing and descending onto and from a vehicle seat has been improved, using a slide mechanism in the seat to effect a fore-and-aft movement of the seat between a seating position and backward position. In particular, the slide mechanism is indispensable for a driver's seat because a steering wheel is projected in front of the seat, which is good during driving the vehicle but a bar against easy climbing and descending of the driver onto and from the seat. Recently, the slide mechanism is electrically controlled by operation of a switch to provide a more improved operationability, so that the driver maY control the slide mechanism to move the seat to a given backward position when he or she climbs onto or descends from the seat.
In view of the seating position being different for an individual occupant, the slide mechanism of this kind has been provided with a microcomputer to memorize a preferred seating position for each occupant and thus the occupant can set his or her own best seating position without having a trouble of re-setting the seating position each time of climbing onto the seat for drive. For this purpose, in a hitherto computerized system, an identification code for each occupant (driver) is utilized: Once placing the identification code in memory of the mircrocomputer, a ready access thereto is made possible by inputting the code from a control board equipped in the vehicle.
However, to set an optimal seating position, the occupant is required to preset and store it in memory through several steps of operations, and where the occupant is a beginner to operate such presetting steps or has not knowledge about his optimal seating position, he or she presets and stores an improper seating position, and further feels it annoying to conduct such code inputting work before climbing onto the seat. Additionally, a repeated movements of the seat between a set seating position and backward position may cause an overrun of the seat beyond the set movement range, which produces and accumulates erroneous code inputs in the microcomputer, with the result that the errors need correcting by a compensation means incorporated in the microcomputer and the control device on the whole becomes too expensive to be assembled. Moreover, as far as a motor control is concerned, there has been no concept in this seat slide control as to the rotation rate adjustment of the motor. Hitherto, the motor has been set at a certain rate for its rotation, and the seat is moved at a moderate speed between the seating and backward postions. This becomes a problem in that an occupant can not control the seat sliding rate (or speed), when he or she wishes to draw backward the seat rapidly or make it move slow for fine adjustment to attain a best seating position.
It is a second purpose of the present invention to alleviate memorization of erroneous input data generated from the overrun of the seat.
For such purpose, shortly before the seat is moved from the seating position to the backward position, the counter resets the memorized rotation number of the motor to zero and starts to count up the same with the backward movement of the seat towards the backward position.
Accordingly, such automatic resetting insures avoiding accumulation of erroneous counts due to the roverrun, and eleminates the need to install a compensation means or CPU.
It is a third purpose of the present invention to facilitate the movement of the seat between the seating and backward positions and meke easy the adjustment of the seating and backward positions.
To this end, there is provided a circuit for changing the rotation rate of the motor, such that the motor is to be rotated at a high rate to move the seat rapidly between the seating and backward positions, whereas the rotation rate of the motor is a low to move the seat slowly in order for the seat to befe finely adjusted its seating and backward positions.
With the above arrangements, the control of the seat sliding motion is carried out without a computer, and the structure of the device is much simplified. The same goes for the operation.
In another aspect of the present invention, there are further provided a hand brake detector, seating detector, reclining angle detector, emergency stop switch, or the like, as a safe protection means, to insure safe controlling of the seat slide motion of the seat.